Before you cut your friend off, you might educate yourself about sex addiction, sex offending, etc. There actually IS a nuanced way of understanding all of it. Clearly he needs help, and I hope he is getting it. But it’s also important to know that just because he got close to offending on the internet doesnt mean he is an out of control pedophile who would molest anyone in real life. Family is different from strangers, internet anonymity is different from not, pubescent is different from child, etc. And, having worked with sex addiction and sex offending for the past 20 years I can tell you that people can, actually, with good treatment, never re-offend. Just in the same way someone could have an affair and yet never do it again. We are not inside of their marriage or inside of his treatment so we dont know the answers to these question. I encourage you to not run with fears and stereotypes but instead really be open to learning all of the nuances and facts and then decide if you want to cut off these 2 people who have become your family.